Interesting Facts About Sea Otters

Sea otters use stones to break open hard-shelled food.

Sea otters appear to be cute animals. They are extremely playful, and float on their backs while eating fish and other marine life. In the wild, sea otters may live up to 23 years of age. Except when mating, sea otters remain solitary, spending most of their lives in the ocean. The furry creatures remain one of the few mammals to exhibit use of tools to help access food.

Location

Sea otters used to live all along the rim of the Northern Pacific, from Japan to Russia and from Alaska down to Mexico. Hunting in the 18th and 19th centuries nearly brought the otters to extinction. Three subspecies of otters still exist, including the Enydra lutris lutris that lives off of Russia. Enhydra lutris nereis lives along Central California's coast while Enhydra lutris kenyoni lives near the Aleutian Islands and southern Alaska. Populations of Enhydra lutris kenyoni have also been introduced from Alaska south to Oregon.

Description

A member of the Mustelidae family, sea otters grow to almost five feet in length, weighing up to 100 pounds when mature. Females appear slightly smaller than the males. A sea otter's tail makes up one-third of its body length. Its brown or reddish fur remains the densest of all mammals, with 100,000 hairs per square centimeter, according to the University of Michigan's Museum of Zoology. Unlike some mammals, seat otters do not rely on a layer of fat to help keep them warm. Instead, they use their fur to stay warm. The otter's long hind legs feature flat, webbed paws. Its shorter front legs have retractable claws.

Diet

Otters eat mussels, crabs, squid, and fish from kelp forests. Foraging takes about 50 to 90 seconds per attempt. Sea otters find prey by using their eyes as well as touch. Otters capture prey with their front paws then bring the food to the surface of the water, where they float on their backs, using their chests as a dining table. Sometimes otters place hard-shelled prey on their chests, then use a rock as a tool to crack the shell open.

Behavior

Sea otters swim by using their hind legs, tail, and the undulating movements of the bodies while they keep their front legs close to their bodies. According to the University of Michigan's Museum of Zoology, otters swim almost six miles per hour and can hold their breath for up to six minutes underwater.

Reproduction

Sea otter males usually mate with more than one female, defending its territory with splashing and vocal displays. The females give birth to one pup that weighs a few pounds. The pup nurses from the mother but also eats solid food soon after birth. Within two months the pup starts diving. The mother provides all care of the pup until it reaches five to six months in age. Female sea otters are sexually mature at about four years of age while the males start mating at about six years of age.

References

• University of Michigan Museum of Zoology: Enhydra lutris
• Monterey Bay Aquarium: Facts About Sea Otters

Resources

• Defenders of Wildlife: Sea Otters